[Typo3] Error in BE with new Extension (Kickstarter)

[Christian Oettinger]

Hi all,


Although I am beginner, this is not my first extension in typo3. But 
it's the first time I'm running in this Problem. I kickstart an 
extension. When I install it, everything is fine, until I create a new 
record on some page and save it.
After that I get the following output on klicking this page (in list 
module):

Warning :  mysql_num_rows(): supplied argument is not a valid MySQL 
result resource in 
/opt/dienste/http/inline/stmartin/htdocs/new/typo3/t3lib/class.t3lib_db.php 
on line 711

Warning :  Cannot modify header information - headers already sent by 
(output started at 
/opt/dienste/http/inline/stmartin/htdocs/new/typo3/t3lib/class.t3lib_db.php:711) 
in /opt/dienste/http/inline/stmartin/htdocs/new/typo3/template.php on 
line 601



(It's a small extenion with only one table, so I don't see too much room 
for mistakes. I already dropped the tables of the extension, overwrote 
it with the kickstarter so that any manual mistakes should be gone and 
cleared the cache a million times.)


does someone have any ideas?

thanks in advance!

christian